Just some more thoughts :-)
Regards
Graeme
Matthew Stanton <matthews at sf.nsw.gov.au> on 03/08/2000 10:18:07 AM
Please respond to rainbowfish at pcug.org.au
To: "'rainbowfish at pcug.org.au'" <rainbowfish at pcug.org.au>
cc: (bcc: Graeme J Finsen/AU/Schneider)
Subject: RE: [RML] Gambusia control
It's nice to hear that someone is thinking about the problem of Gambusia.
I may be incorrect but wasn't it the Mouth Almighty that was implicated in
the demise of the natural inhabitants of Lake Eacham?
Is there any evidence that the natural distribution of Mouth Almighty has
fewer Gambusia than areas further south?
Mouth Almighty is supposedly present in the Tweed, Richmond and Clarence
Rivers but there is still a healthy population of Gambusia in many places
within these systems. Generally you can be assured of finding Gambusia when
you look in agricultural or urban areas or in small overflow ponds.
There are already other predators of Gambusia present in those Rivers. I
recall one occasion when I had been working my way up a small tributary of
the Richmond River, catching a few Rhads, Firetail Gudgeons and Striped
Gudgeons, when I found a small pond with a stream trickling through it. The
pond was packed with Gambusia. I also had a scoop down in the main creek
where I captured a Striped Gudgeon 185 mm long with a huge distended gut.
As
I examined and measured the fish it spewed up a couple of Gambusia.
I think answers to the Gambusia problem are going to have to be based on
something other than vertebrate predation. Perhaps we have some live bearer
breeders on the list who can tell us what their most feared disease
problems
are!?
Matthew
> -----Original Message-----
> From: Bruce Hansen [SMTP:bruceh at powerup.com.au]
> Sent: Wednesday, March 08, 2000 8:58 AM
> To: Rainbowfish Mailing List
> Subject: [RML] Gambusia control
>
> G'day All
>
> Here in Australia, as in many parts of the world, feral populations of
> Gambusia are steadily spreading outwards from areas of development and
the
> disturbed habitats around them into many of the more pristine surrounding
> areas.
>
> Many of these areas contain species and fish communities that may well
> become threatened by the competition.WE also have other feral species
like
> carp and tilapia damaging habitats as well and to a much lesser degree
> some
> more definite aquarium escapees such as guppies,platies and swordtails.
>
> A suggestion has been floated that in colder areas Mouth Almightys
> (Glossamia aprion) might be a useful introduction to Gambusia affected
> areas, The theory is that they be introduced early in the summer, they
eat
> gambusia like mad all summer and die off as soon as the weather gets too
> cold.
>
> I can think of lots of problems with this but at least it is a
> contribution
> aimed at reducing the gambusia menace. Perhaps if habitat/riparian
> restoration is instituted concurrently there may be some merit in it????
>
> Regards,
> Bruce Hansen
> president at angfa.org.au
> Please visit us at http://www.angfa.org.au